Defining and distinguishing homeland from national security and climate-related environmental security, in theory and practice

The worsening effects of human-caused climate change, as well as issues most American view as "homeland security" (HS) can be seen in the news almost every day. Yet most in the general public and even many in security-related fields do not connect the two arenas, even though climate change, and interrelated resource competition and conflicts that together make up the growing field of environmental security (ES), are increasingly important risk and response variables for homeland security and emergency management. Current climate change effects are already destructive and volatile, but the future projected impacts are likely to be severe and costly to the economic, political, and social health of many nations as well as to a large proportion of the world's population. The focus of this paper is to describe and connect the evolving concepts of environmental security, homeland security, and national security (NS). Definitions and missions for each concept are discussed, consistent with current, even if contested, practice and theory. Better comparative analysis of these unique but intimately connected realms will help advance the development of more comprehensive and sustainable security policy and strategy.